Introduction: Preformulation in parenteral dosage forms is a critical stage in B.Pharm training that evaluates physicochemical properties to ensure safe, effective injectable products. This preformulation assessment includes solubility, pKa, partition coefficient, stability (chemical and physical), compatibility with excipients and containers, sterility and endotoxin control, isotonicity, viscosity, and aggregation potential—especially for protein formulations. Understanding analytical tools like HPLC, DSC, FTIR, light scattering, and zeta potential, plus sterilization effects and lyophilization strategies, helps predict formulation behavior and select buffers, surfactants, antioxidants, and tonicity agents. Mastery of these concepts reduces development risks and guides robust parenteral design. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which preformulation parameter primarily predicts a drug’s ability to cross biological membranes for parenteral absorption?
- Melting point
- Partition coefficient (log P)
- Color and odor
- Bulk density
Correct Answer: Partition coefficient (log P)
Q2. For a parenteral aqueous formulation, which property is most critical to adjust to minimize pain and tissue damage on injection?
- pH and isotonicity
- Viscosity only
- Color
- Bulk density
Correct Answer: pH and isotonicity
Q3. Which analytical technique is most appropriate to detect crystallization or glass transitions in a parenteral preformulation study?
- HPLC
- DSC (Differential Scanning Calorimetry)
- Particle counter
- pH meter
Correct Answer: DSC (Differential Scanning Calorimetry)
Q4. Which degradation pathway is of greatest concern for protein parenteral formulations during storage?
- Hydrolysis only
- Aggregation and deamidation
- Melting
- Polymerization into large crystals
Correct Answer: Aggregation and deamidation
Q5. What is the primary reason to perform forced-degradation studies in preformulation for parenterals?
- To determine taste masking requirements
- To identify likely degradation products and stability-indicating methods
- To measure bulk powder flow
- To establish labeling claims
Correct Answer: To identify likely degradation products and stability-indicating methods
Q6. Which excipient class is commonly used in parenteral formulations to prevent protein surface adsorption and agitation-induced aggregation?
- Bulking agents
- Surfactants (e.g., polysorbate 80)
- Dyes
- Sweeteners
Correct Answer: Surfactants (e.g., polysorbate 80)
Q7. When selecting a buffer for an injectable formulation, which criterion is most important?
- Buffer pKa should be close to desired formulation pH
- The buffer should be colored
- Highest possible ionic strength
- Must be a strong oxidizing agent
Correct Answer: Buffer pKa should be close to desired formulation pH
Q8. Which parameter must be controlled to meet regulatory requirements and patient safety for intravenous formulations?
- Particulate matter and sterility
- Tablet hardness
- Disintegration time
- Granule size
Correct Answer: Particulate matter and sterility
Q9. Which method is most suitable to remove bacterial contaminants from a thermolabile parenteral solution without heat sterilization?
- Autoclaving
- Sterile filtration (0.22 µm)
- UV irradiation only
- Freeze–thaw cycles
Correct Answer: Sterile filtration (0.22 µm)
Q10. In preformulation, the measurement of pKa helps predict:
- Particle size distribution
- The ionization state and solubility of the drug at physiological pH
- Endotoxin levels
- Viscosity of the solution
Correct Answer: The ionization state and solubility of the drug at physiological pH
Q11. Which container–closure interaction is a concern for parenteral products during preformulation?
- Glass delamination and adsorption to container surfaces
- Tablet capping
- Pallet deformation
- Granule segregation
Correct Answer: Glass delamination and adsorption to container surfaces
Q12. For isotonic parenteral solutions, which excipient is commonly used as a tonicity agent?
- Sucrose, sodium chloride, or glycerin
- Magnesium stearate
- Talc
- Cellulose powder
Correct Answer: Sucrose, sodium chloride, or glycerin
Q13. Which analytical technique is best to quantify small-molecule degradation products in a parenteral stability study?
- HPLC with appropriate detector
- Microscopy
- Tap density tester
- pH indicator paper
Correct Answer: HPLC with appropriate detector
Q14. What is the primary purpose of a preservative in multi-dose parenteral formulations?
- Enhance flavor
- Prevent microbial growth during repeated entry
- Increase viscosity
- Promote crystallization
Correct Answer: Prevent microbial growth during repeated entry
Q15. Which physical property is most indicative of propensity for injectable solutions to form particulates on agitation?
- Polymorphic form
- Surface tension and presence of interfaces
- Bulk tap density
- Glass transition temperature
Correct Answer: Surface tension and presence of interfaces
Q16. During preformulation, endotoxin testing is mandatory for:
- Topical creams only
- All parenteral products
- Oral tablets only
- Inhalation powders only
Correct Answer: All parenteral products
Q17. Which factor most affects the selection of a lyoprotectant for freeze-drying a protein parenteral?
- Color compatibility
- Ability to stabilize protein structure during freezing and drying
- Cost only
- Melting point above 300°C
Correct Answer: Ability to stabilize protein structure during freezing and drying
Q18. Zeta potential measurement in preformulation is used to assess:
- Chemical degradation rate
- Colloidal stability and propensity to aggregate
- Buffer capacity
- Endotoxin concentration
Correct Answer: Colloidal stability and propensity to aggregate
Q19. Which sterilization method may cause oxidation or degradation of peroxide-sensitive parenteral drugs?
- Filtration through 0.22 µm
- Gamma irradiation or ethylene oxide
- Storage at 4°C
- Lyophilization
Correct Answer: Gamma irradiation or ethylene oxide
Q20. Compatibility studies between drug and excipients in parenterals typically evaluate:
- Only visual color change
- Chemical stability, physical compatibility, and interaction with container closure
- Tablet disintegration time
- Granule flow
Correct Answer: Chemical stability, physical compatibility, and interaction with container closure
Q21. Which parameter is most important when designing an IV bolus formulation versus infusion?
- Color matching to infusion set
- Pulse osmolarity and bolus concentration to avoid toxicity
- Tablet hardness
- Coating uniformity
Correct Answer: Pulse osmolarity and bolus concentration to avoid toxicity
Q22. Which technique is commonly used to detect subvisible particles in parenteral solutions?
- Laser light obscuration or flow imaging microscopy
- pH paper
- UV–Vis color comparison
- Melting point apparatus
Correct Answer: Laser light obscuration or flow imaging microscopy
Q23. A drug with very low aqueous solubility intended for IV use in solution often requires:
- Use of co-solvents, cyclodextrins, or nanoparticle formulation strategies
- A higher compression force
- Palm oil excipients for tablet coating
- Reduction of particle size by milling only for tablets
Correct Answer: Use of co-solvents, cyclodextrins, or nanoparticle formulation strategies
Q24. Which preformulation parameter helps predict chemical hydrolysis risk for an injectable drug?
- Color index
- Presence of hydrolytically labile functional groups and solution pH
- Tablet friability
- Specific surface area of powder
Correct Answer: Presence of hydrolytically labile functional groups and solution pH
Q25. Which preservative is commonly avoided in neonatal parenteral formulations due to toxicity concerns?
- Benzyl alcohol
- Phenol
- Chlorobutanol
- Parabens
Correct Answer: Benzyl alcohol
Q26. During preformulation, the measurement of osmolality for an injectable aims to:
- Ensure patient comfort and avoid hemolysis or vascular irritation
- Determine melting point
- Assess tablet release profile
- Calculate molecular weight
Correct Answer: Ensure patient comfort and avoid hemolysis or vascular irritation
Q27. Which excipient is commonly incorporated to prevent oxidation of parenteral formulations?
- Antioxidants like ascorbic acid or sodium metabisulfite
- Surfactants only
- Bulking agents like mannitol only
- Dyes
Correct Answer: Antioxidants like ascorbic acid or sodium metabisulfite
Q28. A drug that adsorbs to glass or plastic vials may require preformulation assessment of:
- Container material compatibility and surface adsorption studies
- Tablet coating weight
- Granule porosity
- Chewability
Correct Answer: Container material compatibility and surface adsorption studies
Q29. Which factor is most relevant when selecting a syringe filter material for sterile filtration of a protein solution?
- Syringe color
- Low protein-binding membrane material
- High metal content
- Large pore size like 5 µm
Correct Answer: Low protein-binding membrane material
Q30. In preformulation, accelerated stability studies (e.g., 40°C/75% RH) primarily help to:
- Predict long-term stability and identify degradation pathways
- Determine tablet tensile strength
- Measure solubility under all conditions
- Replace the need for sterility testing
Correct Answer: Predict long-term stability and identify degradation pathways
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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